I have a 5/2 yr old Dell desktop, 2.4 GHz, 250 GB hard drive, running Vista
Home (Premium, I think). Lately it’s been getting slower so I finally backed it
up multiple ways and reinstalled Vista from the recovery partition. That
process reformatted the hard drive (supposedly) and installed Vista Home.
Unbelievably the system is now running slower than before. Everything is
slower: boot up, email, Windows Mail, web apps. I’ve reinstalled the last 5/2
years of Windows updates. I’ve not put all my photos back on, so instead of
being 90% full it’s now 40% full. I had MS Security Essentials but removed that
and put AVG free on; just trying something different. No soap. Still very slow.
The AVs and Malwarebytes all say the system is clean. Does a reinstall from a
recovery partition not really wipe everything clean? Should I boot a DOS disc
and repartition and reformat manually? This would blow away the recovery
partition but at this point, I don’t really care. Any light you can shed on the
situation would be very much appreciated.
In this excerpt from
Answercast #69, I look at a case where reinstalling the operating system has
slowed down a computer even more than before!
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Slow after reinstalling
There are two things that come to mind for me – neither of which are
particularly easy to deal with, but they are the things that come to mind.
Continuing malware infection
It is conceivable that malware survives a reformat like this. If malware
manages to infect your recovery partition, which I believe has been known to
happen, then a reformat and reinstall from the recovery partition may in fact
still propagate the malware on to your new machine. It’s conceivable that the
malware itself is running and slowing down your system.
One thing I would do, of course, would be to run Process Explorer to see if
there’s anything untoward running on your machine that you’re not expecting, or
something that’s eating up lots of CPU, or something that’s doing a lot of disk
I/O that you’re not expecting.
Bad sector on hard drive
The other thing that comes to mind, that I think more closely matches the
symptoms that you’ve described (in other words, getting slower after this
reformat) is that you have a marginally bad sector on the hard drive.
In other words, the sector is either bad or going bad, but it’s not
so bad that it can’t be read. It’s bad in that it takes the disk drive
several tries to read it every time it needs to read it. So, the first time
might not work, the second time might not work, the third time it finally gets
it right. I’m thinking one-two-three, but given the speed of computers, it
could be the first hundred times it tries to read that sector it fails, but the
101st time it succeeds.
It’s unclear. It’s hard to say exactly what specifically is going on at that
level, but it is one possible cause for a system slow down.
Why would it be slower now than before?
Well, by reinstalling the operating system, you’ve put things back on the
hard drive in essentially a different place. So, if that bad sector used to
contain say a directory entry for a directory that you accessed infrequently,
then you would experience a slow down only when that particular directory entry
was being accessed.
On the other hand, if now with the reinstall, that sector contains something
important… something that the operating system is reading
frequently, maybe it’s in the paging file, maybe it’s in an operating
system core file, it’s hard to say. But if the operating system is now having
to read it constantly or frequently (and this slow down that I’m talking about,
where the sector itself is not being able to be read reliably), then that would
magnify the impact of that bad sector on the overall speed of your system.
Repair or replace the disk
Now, solutions: there are two that I can think of.
One is this is exactly the kind of scenario that a utility called Spin Rite is designed to
solve. It will actually go through and refresh that sector. It will test the
heck out of it. If that sector’s not going to work, it will mark it as being
bad and move the data around so that it’s no longer being used – and the bad
sectors then no longer impact your performance.
The other solution… because Spin Rite is $95 and $95 can probably buy you
a pretty good hard drive. The other solution would be to back up your entire
hard drive, replace the hard drive, and then restore that new replacement hard
drive from your backup image.
Those are the two different kinds of approaches I would take. I happen to
have Spin Rite already for many different reasons. So, you know, obviously
then, already having paid my $95, I’d absolutely go to Spin Rite right away.
Let it work on the drive and see if that doesn’t resolve the problem. But not
having Spin Rite? Sure, it makes sense that maybe replacing the drive would be
the thing to do in a case like this.
So there’s two options… either malware or the beginnings of a flaky
The malware is something that you can run additional tests on. It’s
something that you can go out and do. I would absolutely make sure that you run
your anti-malware tools against not only the installed system but the recovery
I would actually go so far as to look for some good rootkit tools because
it’s rootkits that often can survive a little bit longer than some of the other
types of malware.
One way to absolutely get rid of the malware is as you described: reinstall
the system from scratch for real – not using the recovery partition. I don’t
think you have to get a boot disc or a DOS disc. I think you can get yourself a
Windows installation disc. You’ll be able to boot from that. That will then
allow you to manipulate the partitions, potentially delete the recovery
partition, reformat the hard drive, and install Windows from scratch – in that
case, installing only the bits that were coming from the installation media
That would be another safe way to make sure you’re avoiding malware as being
the cause of this.
If on the other hand you do all that, you still end up with a slow hard
drive? Then I’d be really, really tempted to replace the hard drive and see if
that doesn’t resolve the issue for you.